1. Technical Field
The present invention relates to a reflection-type screen, a projection system, a front projection television system, and a reflection-type screen manufacturing method.
2. Related Art
A reflection-type screen which receives projection light from a projector or the like and reflects the projection light to display a visually recognizable image is known. A known example of this reflection-type screen is a type which has a number of convex units having uniform shapes disposed two-dimensionally on the front surface of a screen base to which an image is projected (JP-A-2006-215162).
The reflection-type screen disclosed in JP-A-2006-215162 has a reflection surface only on a part of each front surface area of the units facing to the incident direction of the projection light. For example, when the projection image is applied to the reflection-type screen in the diagonally upward direction from the projector disposed on the front side of the reflection-type screen at a position diagonally below the reflection-type screen, the reflection surface for reflecting the projection light is not provided on the upper area of each unit to which the projection light is not applied but is provided only on the lower area of each unit to which the projection light is applied. The reflection surface formed on each lower area of the units can reflect a larger amount of the projection light received from the projector toward the front of the reflection-type screen corresponding to the image viewing side to increase the contrast of the projection image.
According to the reflection-type screen disclosed in JP-A-2006-215162, however, external light other than the projection light such as illumination light from the ceiling is reflected toward the image viewing side when applied to the area of each unit where the reflection surface is not provided. In this case, the reflection of the external light toward the image viewing side may increase the black luminance in the screen characteristics and lower the contrast.